<?php
/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */

/**
 * Converts to and from JSON format.
 *
 * JSON (JavaScript Object Notation) is a lightweight data-interchange
 * format. It is easy for humans to read and write. It is easy for machines
 * to parse and generate. It is based on a subset of the JavaScript
 * Programming Language, Standard ECMA-262 3rd Edition - December 1999.
 * This feature can also be found in  Python. JSON is a text format that is
 * completely language independent but uses conventions that are familiar
 * to programmers of the C-family of languages, including C, C++, C#, Java,
 * JavaScript, Perl, TCL, and many others. These properties make JSON an
 * ideal data-interchange language.
 *
 * This package provides a simple encoder and decoder for JSON notation. It
 * is intended for use with client-side Javascript applications that make
 * use of HTTPRequest to perform server communication functions - data can
 * be encoded into JSON notation for use in a client-side javascript, or
 * decoded from incoming Javascript requests. JSON format is native to
 * Javascript, and can be directly eval()'ed with no further parsing
 * overhead
 *
 * All strings should be in ASCII or UTF-8 format!
 *
 * LICENSE: Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met: Redistributions of source code must retain the
 * above copyright notice, this list of conditions and the following
 * disclaimer. Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
 * NO EVENT SHALL CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
 * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 *
 * @category
 * @package   Services_JSON
 * @author    Michal Migurski <mike-json@teczno.com>
 * @author    Matt Knapp <mdknapp[at]gmail[dot]com>
 * @author    Brett Stimmerman <brettstimmerman[at]gmail[dot]com>
 * @copyright 2005 Michal Migurski
 * @version   CVS: $Id: JSON.php,v 1.31 2006/06/28 05:54:17 migurski Exp $
 * @license   http://www.opensource.org/licenses/bsd-license.php
 * @link      http://pear.php.net/pepr/pepr-proposal-show.php?id=198
 */

/**
 * Marker constant for Services_JSON::decode(), used to flag stack state
 */
define('SERVICES_JSON_SLICE',   1);

/**
* Marker constant for Services_JSON::decode(), used to flag stack state
*/
define('SERVICES_JSON_IN_STR',  2);

/**
* Marker constant for Services_JSON::decode(), used to flag stack state
*/
define('SERVICES_JSON_IN_ARR',  3);

/**
* Marker constant for Services_JSON::decode(), used to flag stack state
*/
define('SERVICES_JSON_IN_OBJ',  4);

/**
* Marker constant for Services_JSON::decode(), used to flag stack state
*/
define('SERVICES_JSON_IN_CMT', 5);

/**
* Behavior switch for Services_JSON::decode()
*/
define('SERVICES_JSON_LOOSE_TYPE', 16);

/**
* Behavior switch for Services_JSON::decode()
*/
define('SERVICES_JSON_SUPPRESS_ERRORS', 32);

/**
 * Converts to and from JSON format.
 *
 * Brief example of use:
 *
 * <code>
 * // create a new instance of Services_JSON
 * $json = new Services_JSON();
 *
 * // convert a complexe value to JSON notation, and send it to the browser
 * $value = array('foo', 'bar', array(1, 2, 'baz'), array(3, array(4)));
 * $output = $json->encode($value);
 *
 * print($output);
 * // prints: ["foo","bar",[1,2,"baz"],[3,[4]]]
 *
 * // accept incoming POST data, assumed to be in JSON notation
 * $input = file_get_contents('php://input', 1000000);
 * $value = $json->decode($input);
 * </code>
 */
class Services_JSON
{
    /**
     * constructs a new JSON instance
     *
     * @param int $use object behavior flags; combine with boolean-OR
     *                 possible values: - SERVICES_JSON_LOOSE_TYPE: 
     *                 loose typing. "{...}" syntax creates
     *                 associative arrays instead of objects in
     *                 decode(). - SERVICES_JSON_SUPPRESS_ERRORS: 
     *                 error suppression. Values which can't be
     *                 encoded (e.g. resources) appear as NULL
     *                 instead of throwing errors. By default, a
     *                 deeply-nested resource will bubble up with an
     *                 error, so all return values from encode()
     *                 should be checked with isError()              
     */
    function Services_JSON($use = 0)
    {
        $this->use = $use;
    }

    /**
     * convert a string from one UTF-16 char to one UTF-8 char
     *
     * Normally should be handled by mb_convert_encoding, but
     * provides a slower PHP-only method for installations
     * that lack the multibye string extension.
     *
     * @param  string $utf16 UTF-16 character
     * @return string  UTF-8 character
     * @access private
     */
    function utf162utf8($utf16)
    {
        // oh please oh please oh please oh please oh please
        if(function_exists('mb_convert_encoding')) {
            return mb_convert_encoding($utf16, 'UTF-8', 'UTF-16');
        }

        $bytes = (ord($utf16[0]) << 8) | ord($utf16[1]);

        switch(true) {
        case ((0x7F & $bytes) == $bytes):
            // this case should never be reached, because we are in ASCII range
            // see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
            return chr(0x7F & $bytes);

        case (0x07FF & $bytes) == $bytes:
            // return a 2-byte UTF-8 character
            // see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
            return chr(0xC0 | (($bytes >> 6) & 0x1F))
                     . chr(0x80 | ($bytes & 0x3F));

        case (0xFFFF & $bytes) == $bytes:
            // return a 3-byte UTF-8 character
            // see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
            return chr(0xE0 | (($bytes >> 12) & 0x0F))
                     . chr(0x80 | (($bytes >> 6) & 0x3F))
                     . chr(0x80 | ($bytes & 0x3F));
        }

        // ignoring UTF-32 for now, sorry
        return '';
    }

    /**
     * convert a string from one UTF-8 char to one UTF-16 char
     *
     * Normally should be handled by mb_convert_encoding, but
     * provides a slower PHP-only method for installations
     * that lack the multibye string extension.
     *
     * @param  string $utf8 UTF-8 character
     * @return string  UTF-16 character
     * @access private
     */
    function utf82utf16($utf8)
    {
        // oh please oh please oh please oh please oh please
        if(function_exists('mb_convert_encoding')) {
            return mb_convert_encoding($utf8, 'UTF-16', 'UTF-8');
        }

        switch(strlen($utf8)) {
        case 1:
            // this case should never be reached, because we are in ASCII range
            // see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
            return $utf8;

        case 2:
            // return a UTF-16 character from a 2-byte UTF-8 char
            // see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
            return chr(0x07 & (ord($utf8[0]) >> 2))
                    . chr(
                        (0xC0 & (ord($utf8[0]) << 6))
                        | (0x3F & ord($utf8[1]))
                    );

        case 3:
            // return a UTF-16 character from a 3-byte UTF-8 char
            // see: http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
            return chr(
                (0xF0 & (ord($utf8[0]) << 4))
                    | (0x0F & (ord($utf8[1]) >> 2))
            )
                    . chr(
                        (0xC0 & (ord($utf8[1]) << 6))
                        | (0x7F & ord($utf8[2]))
                    );
        }

        // ignoring UTF-32 for now, sorry
        return '';
    }

    /**
     * encodes an arbitrary variable into JSON format
     *
     * @param mixed $var any number, boolean, string, array, or object to be encoded.
     *                   see argument 1 to Services_JSON() above for array-parsing
     *                   behavior. if var is a strng, note that encode() always
     *                   expects it to be in ASCII or UTF-8 format!                              
     *
     * @return mixed   JSON string representation of input var or an error if a problem occurs
     * @access public
     */
    function encode($var)
    {
        switch (gettype($var)) {
        case 'boolean':
            return $var ? 'true' : 'false';

        case 'NULL':
            return 'null';

        case 'integer':
            return (int) $var;

        case 'double':
        case 'float':
            return (float) $var;

        case 'string':
            // STRINGS ARE EXPECTED TO BE IN ASCII OR UTF-8 FORMAT
            $ascii = '';
            $strlen_var = strlen($var);

            /*
            * Iterate over every character in the string,
            * escaping with a slash or encoding to UTF-8 where necessary
            */
            for ($c = 0; $c < $strlen_var; ++$c) {

                $ord_var_c = ord($var[$c]);

                switch (true) {
                case $ord_var_c == 0x08:
                    $ascii .= '\b';
                    break;
                case $ord_var_c == 0x09:
                    $ascii .= '\t';
                    break;
                case $ord_var_c == 0x0A:
                    $ascii .= '\n';
                    break;
                case $ord_var_c == 0x0C:
                    $ascii .= '\f';
                    break;
                case $ord_var_c == 0x0D:
                    $ascii .= '\r';
                    break;

                case $ord_var_c == 0x22:
                case $ord_var_c == 0x2F:
                case $ord_var_c == 0x5C:
                    // double quote, slash, slosh
                    $ascii .= '\\'.$var[$c];
                    break;

                case (($ord_var_c >= 0x20) && ($ord_var_c <= 0x7F)):
                    // characters U-00000000 - U-0000007F (same as ASCII)
                    $ascii .= $var[$c];
                    break;

                case (($ord_var_c & 0xE0) == 0xC0):
                    // characters U-00000080 - U-000007FF, mask 110XXXXX
                    // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                    $char = pack('C*', $ord_var_c, ord($var[$c + 1]));
                    $c += 1;
                    $utf16 = $this->utf82utf16($char);
                    $ascii .= sprintf('\u%04s', bin2hex($utf16));
                    break;

                case (($ord_var_c & 0xF0) == 0xE0):
                    // characters U-00000800 - U-0000FFFF, mask 1110XXXX
                    // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                    $char = pack(
                        'C*', $ord_var_c,
                        ord($var[$c + 1]),
                        ord($var[$c + 2])
                    );
                    $c += 2;
                    $utf16 = $this->utf82utf16($char);
                    $ascii .= sprintf('\u%04s', bin2hex($utf16));
                    break;

                case (($ord_var_c & 0xF8) == 0xF0):
                    // characters U-00010000 - U-001FFFFF, mask 11110XXX
                    // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                    $char = pack(
                        'C*', $ord_var_c,
                        ord($var[$c + 1]),
                        ord($var[$c + 2]),
                        ord($var[$c + 3])
                    );
                    $c += 3;
                    $utf16 = $this->utf82utf16($char);
                    $ascii .= sprintf('\u%04s', bin2hex($utf16));
                    break;

                case (($ord_var_c & 0xFC) == 0xF8):
                    // characters U-00200000 - U-03FFFFFF, mask 111110XX
                    // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                    $char = pack(
                        'C*', $ord_var_c,
                        ord($var[$c + 1]),
                        ord($var[$c + 2]),
                        ord($var[$c + 3]),
                        ord($var[$c + 4])
                    );
                    $c += 4;
                    $utf16 = $this->utf82utf16($char);
                    $ascii .= sprintf('\u%04s', bin2hex($utf16));
                    break;

                case (($ord_var_c & 0xFE) == 0xFC):
                    // characters U-04000000 - U-7FFFFFFF, mask 1111110X
                    // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                    $char = pack(
                        'C*', $ord_var_c,
                        ord($var[$c + 1]),
                        ord($var[$c + 2]),
                        ord($var[$c + 3]),
                        ord($var[$c + 4]),
                        ord($var[$c + 5])
                    );
                    $c += 5;
                    $utf16 = $this->utf82utf16($char);
                    $ascii .= sprintf('\u%04s', bin2hex($utf16));
                    break;
                }
            }

            return '"'.$ascii.'"';

        case 'array':
            /*
            * As per JSON spec if any array key is not an integer
            * we must treat the the whole array as an object. We
            * also try to catch a sparsely populated associative
            * array with numeric keys here because some JS engines
            * will create an array with empty indexes up to
            * max_index which can cause memory issues and because
            * the keys, which may be relevant, will be remapped
            * otherwise.
            *
            * As per the ECMA and JSON specification an object may
            * have any string as a property. Unfortunately due to
            * a hole in the ECMA specification if the key is a
            * ECMA reserved word or starts with a digit the
            * parameter is only accessible using ECMAScript's
            * bracket notation.
            */

            // treat as a JSON object
            if (is_array($var) && count($var) && (array_keys($var) !== range(0, sizeof($var) - 1))) {
                $properties = array_map(
                    array($this, 'name_value'),
                    array_keys($var),
                    array_values($var)
                );

                foreach($properties as $property) {
                    if(Services_JSON::isError($property)) {
                        return $property;
                    }
                }

                return '{' . join(',', $properties) . '}';
            }

            // treat it like a regular array
            $elements = array_map(array($this, 'encode'), $var);

            foreach($elements as $element) {
                if(Services_JSON::isError($element)) {
                    return $element;
                }
            }

            return '[' . join(',', $elements) . ']';

        case 'object':
            $vars = get_object_vars($var);

            $properties = array_map(
                array($this, 'name_value'),
                array_keys($vars),
                array_values($vars)
            );

            foreach($properties as $property) {
                if(Services_JSON::isError($property)) {
                    return $property;
                }
            }

            return '{' . join(',', $properties) . '}';

        default:
            return ($this->use & SERVICES_JSON_SUPPRESS_ERRORS)
                    ? 'null'
                    : new Services_JSON_Error(gettype($var)." can not be encoded as JSON string");
        }
    }

    /**
     * array-walking function for use in generating JSON-formatted name-value pairs
     *
     * @param string $name  name of key to use
     * @param mixed  $value reference to an array element to be encoded
     *
     * @return string  JSON-formatted name-value pair, like '"name":value'
     * @access private
     */
    function name_value($name, $value)
    {
        $encoded_value = $this->encode($value);

        if(Services_JSON::isError($encoded_value)) {
            return $encoded_value;
        }

        return $this->encode(strval($name)) . ':' . $encoded_value;
    }

    /**
     * reduce a string by removing leading and trailing comments and whitespace
     *
     * @param $str string      string value to strip of comments and whitespace
     *
     * @return string  string value stripped of comments and whitespace
     * @access private
     */
    function reduce_string($str)
    {
        $str = preg_replace(
            array(

                // eliminate single line comments in '// ...' form
                '#^\s*//(.+)$#m',

                // eliminate multi-line comments in '/* ... */' form, at start of string
                '#^\s*/\*(.+)\*/#Us',

                // eliminate multi-line comments in '/* ... */' form, at end of string
                '#/\*(.+)\*/\s*$#Us'

            ), '', $str
        );

        // eliminate extraneous space
        return trim($str);
    }

    /**
     * decodes a JSON string into appropriate variable
     *
     * @param string $str JSON-formatted string
     *
     * @return mixed   number, boolean, string, array, or object
     *                   corresponding to given JSON input string.
     *                   See argument 1 to Services_JSON() above for object-output behavior.
     *                   Note that decode() always returns strings
     *                   in ASCII or UTF-8 format!
     * @access public
     */
    function decode($str)
    {
        $str = $this->reduce_string($str);

        switch (strtolower($str)) {
        case 'true':
            return true;

        case 'false':
            return false;

        case 'null':
            return null;

        default:
            $m = array();

            if (is_numeric($str)) {
                // Lookie-loo, it's a number

                // This would work on its own, but I'm trying to be
                // good about returning integers where appropriate:
                // return (float)$str;

                // Return float or int, as appropriate
                return ((float)$str == (integer)$str)
                    ? (integer)$str
                    : (float)$str;

            } elseif (preg_match('/^("|\').*(\1)$/s', $str, $m) && $m[1] == $m[2]) {
                // STRINGS RETURNED IN UTF-8 FORMAT
                $delim = substr($str, 0, 1);
                $chrs = substr($str, 1, -1);
                $utf8 = '';
                $strlen_chrs = strlen($chrs);

                for ($c = 0; $c < $strlen_chrs; ++$c) {

                    $substr_chrs_c_2 = substr($chrs, $c, 2);
                    $ord_chrs_c = ord($chrs[$c]);

                    switch (true) {
                    case $substr_chrs_c_2 == '\b':
                        $utf8 .= chr(0x08);
                        ++$c;
                        break;
                    case $substr_chrs_c_2 == '\t':
                        $utf8 .= chr(0x09);
                        ++$c;
                        break;
                    case $substr_chrs_c_2 == '\n':
                        $utf8 .= chr(0x0A);
                        ++$c;
                        break;
                    case $substr_chrs_c_2 == '\f':
                        $utf8 .= chr(0x0C);
                        ++$c;
                        break;
                    case $substr_chrs_c_2 == '\r':
                        $utf8 .= chr(0x0D);
                        ++$c;
                        break;

                    case $substr_chrs_c_2 == '\\"':
                    case $substr_chrs_c_2 == '\\\'':
                    case $substr_chrs_c_2 == '\\\\':
                    case $substr_chrs_c_2 == '\\/':
                        if (($delim == '"' && $substr_chrs_c_2 != '\\\'') 
                            || ($delim == "'" && $substr_chrs_c_2 != '\\"')
                        ) {
                            $utf8 .= $chrs[++$c];
                        }
                        break;

                    case preg_match('/\\\u[0-9A-F]{4}/i', substr($chrs, $c, 6)):
                        // single, escaped unicode character
                        $utf16 = chr(hexdec(substr($chrs, ($c + 2), 2)))
                               . chr(hexdec(substr($chrs, ($c + 4), 2)));
                        $utf8 .= $this->utf162utf8($utf16);
                        $c += 5;
                        break;

                    case ($ord_chrs_c >= 0x20) && ($ord_chrs_c <= 0x7F):
                        $utf8 .= $chrs[$c];
                        break;

                    case ($ord_chrs_c & 0xE0) == 0xC0:
                        // characters U-00000080 - U-000007FF, mask 110XXXXX
                        //see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                        $utf8 .= substr($chrs, $c, 2);
                        ++$c;
                        break;

                    case ($ord_chrs_c & 0xF0) == 0xE0:
                        // characters U-00000800 - U-0000FFFF, mask 1110XXXX
                        // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                        $utf8 .= substr($chrs, $c, 3);
                        $c += 2;
                        break;

                    case ($ord_chrs_c & 0xF8) == 0xF0:
                        // characters U-00010000 - U-001FFFFF, mask 11110XXX
                        // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                        $utf8 .= substr($chrs, $c, 4);
                            $c += 3;
                        break;

                    case ($ord_chrs_c & 0xFC) == 0xF8:
                        // characters U-00200000 - U-03FFFFFF, mask 111110XX
                        // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                        $utf8 .= substr($chrs, $c, 5);
                        $c += 4;
                        break;

                    case ($ord_chrs_c & 0xFE) == 0xFC:
                        // characters U-04000000 - U-7FFFFFFF, mask 1111110X
                        // see http://www.cl.cam.ac.uk/~mgk25/unicode.html#utf-8
                        $utf8 .= substr($chrs, $c, 6);
                        $c += 5;
                        break;

                    }

                }

                return $utf8;

            } elseif (preg_match('/^\[.*\]$/s', $str) || preg_match('/^\{.*\}$/s', $str)) {
                // array, or object notation

                if ($str[0] == '[') {
                    $stk = array(SERVICES_JSON_IN_ARR);
                    $arr = array();
                } else {
                    if ($this->use & SERVICES_JSON_LOOSE_TYPE) {
                        $stk = array(SERVICES_JSON_IN_OBJ);
                        $obj = array();
                    } else {
                        $stk = array(SERVICES_JSON_IN_OBJ);
                        $obj = new stdClass();
                    }
                }

                array_push(
                    $stk, array('what'  => SERVICES_JSON_SLICE,
                                       'where' => 0,
                                       'delim' => false)
                );

                $chrs = substr($str, 1, -1);
                $chrs = $this->reduce_string($chrs);

                if ($chrs == '') {
                    if (reset($stk) == SERVICES_JSON_IN_ARR) {
                        return $arr;

                    } else {
                        return $obj;

                    }
                }

                //print("\nparsing {$chrs}\n");

                $strlen_chrs = strlen($chrs);

                for ($c = 0; $c <= $strlen_chrs; ++$c) {

                    $top = end($stk);
                    $substr_chrs_c_2 = substr($chrs, $c, 2);

                    if (($c == $strlen_chrs) || (($chrs[$c] == ',') && ($top['what'] == SERVICES_JSON_SLICE))) {
                        // found a comma that is not inside a string, array, etc.,
                        // OR we've reached the end of the character list
                        $slice = substr($chrs, $top['where'], ($c - $top['where']));
                        array_push($stk, array('what' => SERVICES_JSON_SLICE, 'where' => ($c + 1), 'delim' => false));
                        //print("Found split at {$c}: ".substr($chrs, $top['where'], (1 + $c - $top['where']))."\n");

                        if (reset($stk) == SERVICES_JSON_IN_ARR) {
                            // we are in an array, so just push an element onto the stack
                            array_push($arr, $this->decode($slice));

                        } elseif (reset($stk) == SERVICES_JSON_IN_OBJ) {
                            // we are in an object, so figure
                            // out the property name and set an
                            // element in an associative array,
                            // for now
                            $parts = array();

                            if (preg_match('/^\s*(["\'].*[^\\\]["\'])\s*:\s*(\S.*),?$/Uis', $slice, $parts)) {
                                // "name":value pair
                                $key = $this->decode($parts[1]);
                                $val = $this->decode($parts[2]);

                                if ($this->use & SERVICES_JSON_LOOSE_TYPE) {
                                    $obj[$key] = $val;
                                } else {
                                    $obj->$key = $val;
                                }
                            } elseif (preg_match('/^\s*(\w+)\s*:\s*(\S.*),?$/Uis', $slice, $parts)) {
                                // name:value pair, where name is unquoted
                                $key = $parts[1];
                                $val = $this->decode($parts[2]);

                                if ($this->use & SERVICES_JSON_LOOSE_TYPE) {
                                    $obj[$key] = $val;
                                } else {
                                    $obj->$key = $val;
                                }
                            }

                        }

                    } elseif ((($chrs[$c] == '"') || ($chrs[$c] == "'")) && ($top['what'] != SERVICES_JSON_IN_STR)) {
                        // found a quote, and we are not inside a string
                        array_push($stk, array('what' => SERVICES_JSON_IN_STR, 'where' => $c, 'delim' => $chrs[$c]));
                        //print("Found start of string at {$c}\n");

                    } elseif (($chrs[$c] == $top['delim']) 
                        && ($top['what'] == SERVICES_JSON_IN_STR) 
                        && ((strlen(substr($chrs, 0, $c)) - strlen(rtrim(substr($chrs, 0, $c), '\\'))) % 2 != 1)
                    ) {
                        // found a quote, we're in a string, and it's not escaped
                        // we know that it's not escaped becase there is _not_ an
                        // odd number of backslashes at the end of the string so far
                        array_pop($stk);
                        //print("Found end of string at {$c}: ".substr($chrs, $top['where'], (1 + 1 + $c - $top['where']))."\n");

                    } elseif (($chrs[$c] == '[') 
                        && in_array($top['what'], array(SERVICES_JSON_SLICE, SERVICES_JSON_IN_ARR, SERVICES_JSON_IN_OBJ))
                    ) {
                        // found a left-bracket, and we are in an array, object, or slice
                        array_push($stk, array('what' => SERVICES_JSON_IN_ARR, 'where' => $c, 'delim' => false));
                        //print("Found start of array at {$c}\n");

                    } elseif (($chrs[$c] == ']') && ($top['what'] == SERVICES_JSON_IN_ARR)) {
                        // found a right-bracket, and we're in an array
                        array_pop($stk);
                        //print("Found end of array at {$c}: ".substr($chrs, $top['where'], (1 + $c - $top['where']))."\n");

                    } elseif (($chrs[$c] == '{') 
                        && in_array($top['what'], array(SERVICES_JSON_SLICE, SERVICES_JSON_IN_ARR, SERVICES_JSON_IN_OBJ))
                    ) {
                        // found a left-brace, and we are in an array, object, or slice
                        array_push($stk, array('what' => SERVICES_JSON_IN_OBJ, 'where' => $c, 'delim' => false));
                        //print("Found start of object at {$c}\n");

                    } elseif (($chrs[$c] == '}') && ($top['what'] == SERVICES_JSON_IN_OBJ)) {
                        // found a right-brace, and we're in an object
                        array_pop($stk);
                        //print("Found end of object at {$c}: ".substr($chrs, $top['where'], (1 + $c - $top['where']))."\n");

                    } elseif (($substr_chrs_c_2 == '/*') 
                        && in_array($top['what'], array(SERVICES_JSON_SLICE, SERVICES_JSON_IN_ARR, SERVICES_JSON_IN_OBJ))
                    ) {
                        // found a comment start, and we are in an array, object, or slice
                        array_push($stk, array('what' => SERVICES_JSON_IN_CMT, 'where' => $c, 'delim' => false));
                        $c++;
                        //print("Found start of comment at {$c}\n");

                    } elseif (($substr_chrs_c_2 == '*/') && ($top['what'] == SERVICES_JSON_IN_CMT)) {
                        // found a comment end, and we're in one now
                        array_pop($stk);
                        $c++;

                        for ($i = $top['where']; $i <= $c; ++$i) {
                            $chrs = substr_replace($chrs, ' ', $i, 1);
                        }

                        //print("Found end of comment at {$c}: ".substr($chrs, $top['where'], (1 + $c - $top['where']))."\n");

                    }

                }

                if (reset($stk) == SERVICES_JSON_IN_ARR) {
                    return $arr;

                } elseif (reset($stk) == SERVICES_JSON_IN_OBJ) {
                    return $obj;

                }

            }
        }
    }

    /**
     * @todo Ultimately, this should just call PEAR::isError()
     */
    function isError($data, $code = null)
    {
        /*
        if (class_exists('pear')) {
            return PEAR::isError($data, $code);
        } else
        */
        if (is_object($data) && (get_class($data) == 'services_json_error' 
            || is_subclass_of($data, 'services_json_error'))
        ) {
            return true;
        }

        return false;
    }
}


/**
 * @todo Ultimately, this class shall be descended from PEAR_Error
 */
class Services_JSON_Error
{
    function Services_JSON_Error($message = 'unknown error', $code = null,
        $mode = null, $options = null, $userinfo = null
    ) {

    }
}


 
?>
